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通过1993年召开的全国第二次旧砂再生会,本年度在国内公开出版的杂志上发表的文章有所增多计20余篇,现分四个方面简介.
Through the second national convention for the recycling of used sand held in 1993, more than 20 articles have been published in domestic public magazines this year, which is divided into four chapters.